U.S. patent number 4,439,496 [Application Number 06/372,818] was granted by the patent office on 1984-03-27 for water-proof photographic support.
This patent grant is currently assigned to Fuji Photo Film Co., Ltd.. Invention is credited to Tetsuro Fuchizawa, Minoru Ono, Shigehisa Tamagawa.
United States Patent |
4,439,496 |
Tamagawa , et al. |
March 27, 1984 |
Water-proof photographic support
Abstract
A water-proof photographic support comprising a paper sheet
coated with a polyolefin on both surfaces thereof, in which the
paper sheet contains an alkylketene dimer, a cationic
polyacrylamide and an anionic polyacrylamide.
Inventors: |
Tamagawa; Shigehisa
(Fujinomiya, JP), Fuchizawa; Tetsuro (Fujinomiya,
JP), Ono; Minoru (Tokyo, JP) |
Assignee: |
Fuji Photo Film Co., Ltd.
(Kanagawa, JP)
|
Family
ID: |
13766727 |
Appl.
No.: |
06/372,818 |
Filed: |
April 28, 1982 |
Foreign Application Priority Data
|
|
|
|
|
May 29, 1981 [JP] |
|
|
56-82162 |
|
Current U.S.
Class: |
428/513; 428/514;
428/516; 428/522; 430/536 |
Current CPC
Class: |
G03C
1/79 (20130101); Y10T 428/31913 (20150401); Y10T
428/31935 (20150401); Y10T 428/31906 (20150401); Y10T
428/31902 (20150401) |
Current International
Class: |
G03C
1/775 (20060101); G03C 1/79 (20060101); B32B
023/08 (); B32B 027/08 (); D21H 003/44 () |
Field of
Search: |
;428/513,514,516,522
;162/168.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Ives; P.
Attorney, Agent or Firm: Toren, McGeady and Stanger
Claims
We claim:
1. A water-proof photographic support comprising a paper sheet
coated with a polyolefin on both surfaces thereof, in which the
paper sheet is sized with a combination of an alkylketene dimer, a
cationic polyacrylamide and an anionic polyacrylamide, the
alkylketene dimer being present in an amount of 0.2 to 3.0% by
weight and the total amount of cationic polyacrylamide and anionic
polyacrylamide being 0.5 to 4.0% by weight, all percent by weight
being based on the weight of the absolutely dried pulp constituting
the paper sheet.
2. The water-proof photographic support as claimed in claim 1, in
which the proportion of the cationic polyacrylamide against the
anionic polyacrylamide is in the range of 1/4 to 4/1 by weight.
3. The water-proof photographic support as claimed in claim 1, in
which the alkylketene dimer has an alkyl group containing 8-30
carbon atoms.
4. The water-proof photographic support as claimed in claim 1, in
which the alkylketene dimer has an alkyl group containing 12-18
carbon atoms.
5. The water-proof photographic support as claimed in claim 1, in
which the cationic polyacrylamide has the molecular weight ranging
from 100,000 to 2,000,000.
6. The water-proof photographic support as claimed in claim 1, in
which the cationic polyacrylamide has the molecular weight ranging
from 500,000 to 1,000,000.
7. The water-proof photographic support as claimed in claim 1, in
which the cationic polyacrylamide is selected from the group
consisting of a Mannich modification product of polyacrylamide, a
Hofmann degradation product of polyacrylamide, a reaction product
between polyacrylamide and polyethyleneimine, and a copolymer of
acrylamide with a cationic monomer.
8. The water-proof photographic support as claimed in claim 1, in
which the anionic polyacrylamide has the molecular weight ranging
from 100,000 to 2,000,000.
9. The water-proof photographic support as claimed in claim 1, in
which the anionic polyacrylamide has the molecular weight ranging
from 500,000 to 1,000,000.
10. The water-proof photographic support as claimed in claim 1, in
which the anionic polyacrylamide is selected from the group
consisting of a partially hydrolyzed product of polyacrylamide, an
acrylamide-acrylic acid copolymer, an acrylamide-methacrylic acid
copolymer, an acrylamide-maleic anhydride copolymer, an
acrylamide-acrylic acid-acrylonitrile copolymer, and an
acrylamide-acrylic acid-acrylic acid ester copolymer.
Description
This invention relates to a water-proof photographic support, and
particularly relates to a water-proof photographic support
substantially free from being soiled by a developing solution at
the edge portion produced by the cutting procedure.
There has been previously employed, as the photographic support, a
baryta paper consisting of a paper coated with a baryta layer
comprising mainly barium sulfate on one surface. Recently, however,
a water-proof photographic support comprising a paper sheet coated
with a hydrophobic polyolefin on both surfaces thereof has been
developed and employed to cope with the requirement of a rapid
development process with an automation system. At the present time,
most of the baryta papers have been replaced with the water-proof
photographic support.
Nevertheless, even though the water-proof polyolefin layers are
provided to the both surfaces, the water-proof photographic support
is apt to be soiled by a developing solution at the edge portion
produced by the cutting procedure, because the hydrophilic wood
pulp fibers constituting the paper sheet are liable to draw the
developing solution into the paper sheet from the exposed edge
portion. The so-produced edge soiling can be satisfactorily reduced
by washing sufficiently the developed photographic paper with water
for a long time. However, the washing procedure for a long time is
naturally adverse to the requirement for reduction of the
development time. For this reason, a measure for preventing
permeation of a developing solution from the edge portion has been
earnestly studied.
Until now, there is known and generally employed a measure for
preventing permeation of a developing solution which involves
incorporation of a sizing agent into the paper sheet. However,
there necessarily arise various limitations to the sizing agent
employable for the purpose, in view of the employment in the
specific art of photographic paper. For instance, the sizing agent
to be employed should be effective against permeation of either an
alkaline or an alcohol such as most generally employed benzyl
alcohol, both of which are contained in a developing solution.
Moreover, the sizing agent should not decrease whiteness of the
photographic paper and should not give any adverse effect to an
image produced on the photographic paper such as production of fog.
Accordingly, sizing agents generally employable for sizing a paper
such as a rosin size and a petroleum resin size are not employable
for sizing a paper sheet of the photographic support.
In view of the above-described requirements, there have been
proposed a number of specific sizing agents for the use in the
photographic support, such as a fatty acid soap sizing agent
disclosed in Japanese Patent Publication No. 47(1972)-26,961 and an
alkylketene dimer disclosed in Japanese Patent Provisional
Publication No. 51(1976)-132,822. These sizing agents, however, are
not considered to be satisfactory, because these sizing agents have
certain drawbacks. More in detail, the fatty acid soap sizing agent
is effective for prevention of permeation of the alcohol, while it
is less effective against permeation of the alkaline solution.
Moreover, the fatty acid soap is liable to be influenced by the
quality of water employed in paper making. For instance, the fatty
acid soap precipitates in a hard water to impart poor sizing effect
to the paper sheet and/or to bring about disadvantageous features
in the paper making proces. On the other hand, the alkylketene
dimer is effective for preventing permeation of an alkaline
solution contained in a developing solution, while it is extremely
poor in preventing permeation of the alcohol. Moreover, the
satisfactory prevention of permeation of the alkaline solution by
the alkylketene dimer is accomplished only in the case where a
relatively large amount of a preserving agent, that is, a
polyamide-polyamine-epichlorohydrin resin is employed together with
the alkylketene dimer. Thus, there has not been known a
satisfactory sizing agent for the employment in a photographic
support.
The object of the invention, accordingly, is to provide a
photographic support capable of effectively keeping either an
alkaline solution or an alcohol from permeation into the paper
sheet, whereby enabling production of a photographic paper
substantially free from the edge soiling, that is, substantially
free from being soiled by a developing solution at the edge
portion.
Another object of the invention is to provide a photographic
support having high stiffness.
A further object of the invention is to provide a photographic
support that can be converted to a photographic paper substantially
free from the edge soiling and further free from disadvantageous
photographic features such as formation of fog.
The present inventors have studied on a variety of chemical
compounds for accomplishing the above-described objects, and have
found that the objects are accomplished by sizing the paper sheet
to be incorporated into the photograhic support with a combination
of an alkylketene dimer, a cationic polyacrylamide, and an anionic
polyacrylamide. A photographic paper comprising the so sized paper
sheet is remarkably resistant to permeation of a developing
solution, as compared with photographic papers comprising a paper
sheet sized with one of these compounds.
Accordingly, the present invention resides in a water-proof
photographic support comprising a paper sheet coated with a
polyolefin on both surfaces thereof, in which the paper sheet
contains an alkylketene dimer, a cationic polyacrylamide, and an
anionic polyacrylamide.
The cationic polyacrylamide of the invention can be selected from
materials generally employed as the paper strength increasing
agents. Such materials are described, for instance, in
Kohbunshi-Ronbun-Shu (Collective Edition of Papers Concerning
Polymers), vol. 33, No. 6, p. 309-316 (1970), Japanese Patent
Publications No. 52 (1977)-47,043 and No. 53(1978)-45,411, and
Japanese Patent Provisional Publication No. 55(1980)-6,556.
Examples of cationic polyacrylamides preferably employable for the
invention include a Mannich modification product of polyacrylamide,
a Hofmann degradation product of polyacrylamide, a reaction product
between polyacrylamide and polyethyleneimine, and a copolymer of
acrylamide with a cationic monomer such as dimethylaminoethyl
methacrylate. The cationic polyacrylamide preferably has the
molecular weight ranging from 100,000 to 2,000,000, preferably the
molecular weight ranging from 500,000 to 1,000,000.
The anionic polyacrylamide of the invention can be a partially
hydrolyzed product of polyacrylamide, an acrylamide-acrylic acid
copolymer, an acrylamide-methacrylic acid copolymer, an
acrylamide-maleic anhydride copolymer, an acrylamide-acrylic
acid-acrylonitrile copolymer, and an acrylamide-acrylic acid ester
copolymer as disclosed in Resins for Processing Paper and Fabrics
and Their Evaluation Method (in the Japanese Language, published by
Shohko-do, 1968), p. 283. The anionic polyacrylamide preferably has
the molecular weight ranging from 100,000 to 2,000,000, preferably
the molecular weight ranging from 500,000 to 1,000,000.
The alkylketene dimer preferably has an alkyl group containing 8-30
carbon atoms, and more preferably has an alkyl group containing
12-18 carbon atoms. Examples of the alkylketene dimers include
those disclosed in the afore-cited Japanese Patent Provisional
Publication No. 51(1976)-132,822 and Tappi, vol. 39, No. 1, p.
21-23 (1956, Technical Association of the Pulp and Paper Industry
Inc.). Representative examples of the alkylketene dimers preferably
employable for the invention include dodecylketene dimer,
tridecylketene dimer, tetradecylketene dimer, pentadecylketene
dimer, hexadecylketene dimer, heptadecylketene dimer, and
octadecylketene dimer. Mixtures of these alkylketene dimers can be
also employed for the purpose.
In this invention, a combination of a cationic polyacrylamide, an
anionic polyacrylamide and the alkylketene dimer can be
simultaneously or separately incorporated into or applied to a
paper sheet by the internal sizing method or the surface sizing
method, respectively. The internal sizing method is preferred.
In carrying out the internal sizing method, the alkylketene dimer
together with the cationic and anionic polyacrylamides is
introduced into a pulp slurry, and then a paper is manufactured
from the slurry in a conventional way. Thus, the alkylketene dimer
and the cationic and anionic polyacrylamides are not only provided
to the surface of the paper sheet, but also incorporated into the
inside of the paper sheet.
In carrying out the surface sizing method, a mixture of an
alkylketene dimer, an anionic polyacrylamide and a cationic
polyacrylamide is applied to a surface of a paper sheet to coat the
sheet with the so-applied mixture.
In the present invention, the alkylketene dimer is preferably
contained in the paper sheet in an amount of 0.2-3.0% by weight
based on the absolutely dried pulp constituting the paper sheet.
The cationic polyacrylamide and the aninonic polyacrylamide are
preferably contained in the paper sheet in a total amount of
0.5-4.0% by weight based on the absolutely dried pulp constituting
the paper sheet. The proportion of the cationic polyacrylamide
against the anionic polyacrylamide preferably is in the range of
1/4 to 4/1 by weight.
There is no limitation on nature of the pulp constituting the paper
sheet, as far as it belongs to those employable in the manufacture
of the paper sheets for photographic supports. Examples of the pulp
materials include cellulose-type pulps such as wood pulps, esparto
pulps, and straw pulps. A part of the cellulosetype pulp material
can be replaced with a synthetic pulp material.
In the conventional paper manufacturing art, it is well known to
incorporate into a paper one or more appropriate agents such as a
paper strength increasing agent, a fixing agent, a preserving
agent, a filler, a dye and an antistatic agent, as well as a sizing
agent. In the present invention, the incorporation of these agents
can be also done, as far as such incorporation does not bring about
adverse effects to the photographic support of the invention. Also
permissible is incorporation of a sizing agent other than those
specified in the invention, as far as such incorporation does not
impart adverse effects to the photographic support of the
invention.
The paper sheet containing the alkylketene dimer, the cationic
polyacrylamide and the anionic polyacrylamide is then coated on
both surfaces with a polyolefin in a conventional way to prepare a
photographic support. A polyolefin generally is polyethylene which
is an ethylene homopolymer or a copolymer of ethylene and one or
more of copolymerizable monomers. In the polyethylene copolymer,
the copolymerizable monomer preferably monomer preferably amounts
to not more than 10% by weight of the ethylene content. Examples of
the copolymerizable monomers include alfa-olefins such as propylene
and butene-1; vinyl compounds such as styrene, vinyl stearate,
vinyl acetate, acrylic acid, methyl acrylate, ethyl acrylate,
acrylamide, methacrylic acid, methyl methacrylate, ethyl
methacrylate, and methacrylamide; and diene compounds such as
butadiene and isoprene.
The photographic support of the invention contains, as described
hereinabove, the alkylketene dimer, the cationic polyacrylamide,
and the anionic polyacrylamide in the paper sheet layer provided
between the polyolefin coating layers. This paper sheet layer is
prominently resistant to permeation of a developing solution
comprising an alkaline solution and an alcohol. This prominent
resistance of the paper sheet layer to a developing solution
comprising both of the alkaline solution and the alcohol cannot be
accomplished if the paper sheet layer contains only one of the
combination of the alkylketene dimer, the cationic polyacrylamide,
and the anionic polyacrylamide. Moreover, the photographic support
of the invention has high stiffness due to the incorporation of the
three specific compounds. This high stiffness of the photographic
support of the invention cannot be accomplished if the paper sheet
layer contains only one of the combination of the three specific
compounds.
For the reasons described above, a photographic paper prepared from
the photographic support of the invention shows remarkably reduced
edge soiling caused in the development process by permeation of a
developing solution from the exposed section face of the paper
sheet layer produced by cutting, as compared with conventional
photographic papers. Moreover, the soprepared photographic paper
shows very high stiffness, as compared with conventional
photographic papers.
The present invention is further illustrated by the following
examples, which are by no way intended to restrict the
invention.
EXAMPLES
(1) Preparation of Test Samples
To an aqueous slurry containing wood pulp fibers (LBKP/NBKP=2/1)
beaten to the Canadian freeness level 240 cc. was added
polyamide-polyamine-epichlorohydrin (Kymene 557, trade mark of
DIC-HERCULES CO., Ltd., Japan) in the amount of 0.5% by weight
(based on the absolutely dried pulp content, the same hereinafter)
as a preserving agent. Further added were cationic polyacrylamide
(Polystron 705, trade mark of Arakawa Chemicals Co., Ltd., Japan)
and anionic polyacrylamide (Polyacron ST-13, trade mark of Hamano
Industries Co., Ltd., Japan), both in the amounts set forth in
Table 1. Furthermore, alkylketene dimer having an alkyl group of
14-16 carbon atoms (Aquapel, trade mark of the DIC-HERCULES Co.,
Ltd.) was added to the slurry in the amount of 0.4% by weight. The
pulp slurry was then processed in a conventional way to give a
paper sheet of the basis weight 170 g/m.sup.2.
One surface (back surface) of the paper sheet was coated with
polyethylene of the density of approximately 0.980 g/cm.sup.3 to
form a coating layer of approximately 0.033 mm thick. Another
surface (front surface) of the paper sheet was then coated with
polyethylene of the density of approximately 0.960 g/cm.sup.3
containing titanium dioxide (10% by weight) to form a coating layer
of approximately 0.030 mm thick. Thus, water-proof photographic
supports were prepared.
TABLE 1 ______________________________________ Test Sample Cationic
Polyacrylamide Anionic Polyacrylamide No. Amount Amount
______________________________________ 1* 0 0 2* 0 1.0 3 0.3 0.7 4
0.5 0.5 5 0.7 0.3 6* 1.0 0 ______________________________________
Note: Test Samples No. 1, No. 2 and No. 6 given the asterisk all
represen test samples for comparison purpose.
The six test samples were then subjected to evaluation on the edge
soiling liability and evaluation on stiffness.
The edge-soiling evaluation was carried out by the following
procedures: the photographic support sample was cut to produce a
test strip of 8.25 cm wide. The test strip was then developed in
Automatic Color Paper Development Apparatus RPV-409 Type (available
from Noritu Koki Co., Ltd., Japan), and subjected to eye
measurement through a loupe of the depth of developing solution
permeation from the edge section face.
The stiffness was determined by means of a Taber Stiffness
measurement in accordance with JIS-P-8125.
The results of the evaluation are set forth in Table 2.
TABLE 2 ______________________________________ Test Sample Depth of
Permeation of Stiffness No. Developing solution (mm) (g)
______________________________________ 1* 0.75 9.8 2* 0.76 10.2 3
0.42 11.5 4 0.32 12.6 5 0.30 11.2 6* 0.57 10.1
______________________________________ Note: Test Samples No. 1,
No. 2 and No. 6 given the asterisk all represen test samples for
comparison purpose.
The results set forth in Table 2 clearly indicate that the
water-proof photographic support of the invention is remarkably
improved in the edge soiling liability and the stiffness, as
compared with the conventional water-proof photographic supports
represented by the Comparison Test Samples No. 1, No. 2, and No.
6.
* * * * *